scholarly journals Mice deficient in the lysosomal enzyme palmitoyl-protein thioesterase 1 (PPT1) display a complex retinal phenotype

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yevgeniya Atiskova ◽  
Susanne Bartsch ◽  
Tatyana Danyukova ◽  
Elke Becker ◽  
Christian Hagel ◽  
...  

Abstract Neuronal ceroid lipofuscinosis (NCL) type 1 (CLN1) is a neurodegenerative storage disorder caused by mutations in the gene encoding the lysosomal enzyme palmitoyl-protein thioesterase 1 (PPT1). CLN1 patients suffer from brain atrophy, mental and motor retardation, seizures, and retinal degeneration ultimately resulting in blindness. Here, we performed an in-depth analysis of the retinal phenotype of a PPT1-deficient mouse, an animal model of this condition. Reactive astrogliosis and microgliosis were evident in mutant retinas prior to the onset of retinal cell loss. Progressive accumulation of storage material, a pronounced dysregulation of various lysosomal proteins, and accumulation of sequestosome/p62-positive aggregates in the inner nuclear layer also preceded retinal degeneration. At advanced stages of the disease, the mutant retina was characterized by a significant loss of ganglion cells, rod and cone photoreceptor cells, and rod and cone bipolar cells. Results demonstrate that PPT1 dysfunction results in early-onset pathological alterations in the mutant retina, followed by a progressive degeneration of various retinal cell types at relatively late stages of the disease. Data will serve as a reference for future work aimed at developing therapeutic strategies for the treatment of retinal degeneration in CLN1 disease.

1994 ◽  
Vol 11 (2) ◽  
pp. 379-387 ◽  
Author(s):  
Elena V. Grigorenko ◽  
Hermes H. Yeh

AbstractThis study profiled the expression of the family of GABAA receptor β-subunits in the adult rat retina. Using a combination of reverse transcriptase reaction followed by polymerase chain reaction (RT-PCR) with gene-specific primers, the expression of mRNAs encoding the β1, β2, and β3 subunits was first examined in the intact retina and then in separated retinal nuclear layers. However, it was found that a critical analysis. had to be carried out at the level of the single cell in order to resolve the differential patterns of expression among the retinal cell types. When cells were isolated and identified following acute dissociation, RT-PCR revealed that individual rod photoreceptor cells expressed consistently the β1 and β2 messages while the bipolar cells expressed the β1 and β3 messages. Ganglion cells displayed considerable variability in β-subunit expression, perhaps reflecting their functional and morphological heterogeneity in the retina. In contrast, the nonneuronal Mueller cells did not express any of the β-subunit messages. These results indicate that the expression of GABAA receptor subunits is cell-type dependent. Furthermore, as the expression of other families of GABAA receptor subunits are profiled and the patterns of subunit assembly are better understood, our results raise the possibility that GABAA receptors with different subunit compositions can be expected to be coexpressed within a single retinal neuron.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 696
Author(s):  
Mahmoud Bassal ◽  
Junling Liu ◽  
Wanda Jankowiak ◽  
Paul Saftig ◽  
Udo Bartsch

Vision loss is among the characteristic symptoms of neuronal ceroid lipofuscinosis (NCL), a fatal neurodegenerative lysosomal storage disorder. Here, we performed an in-depth analysis of retinal degeneration at the molecular and cellular levels in mice lacking the lysosomal aspartyl protease cathepsin D, an animal model of congenital CLN10 disease. We observed an early-onset accumulation of storage material as indicated by elevated levels of saposin D and subunit C of the mitochondrial ATP synthase. The accumulation of storage material was accompanied by reactive astrogliosis and microgliosis, elevated expression of the autophagy marker sequestosome 1/p62 and a dysregulated expression of several lysosomal proteins. The number of cone photoreceptor cells was reduced as early as at postnatal day 5. At the end stage of the disease, the outer nuclear layer was almost atrophied, and all cones were lost. A significant loss of rod and cone bipolar cells, amacrine cells and ganglion cells was found at advanced stages of the disease. Results demonstrate that cathepsin D deficiency results in an early-onset and rapidly progressing retinal dystrophy that involves all retinal cell types. Data of the present study will serve as a reference for studies aimed at developing treatments for retinal degeneration in CLN10 disease.


2001 ◽  
Vol 18 (4) ◽  
pp. 559-570 ◽  
Author(s):  
B.E. REESE ◽  
M.A. RAVEN ◽  
K.A. GIANNOTTI ◽  
P.T. JOHNSON

The present study has examined the emergence of cholinergic stratification within the developing inner plexiform layer (IPL), and the effect of ablating the cholinergic amacrine cells on the formation of other stratifications within the IPL. The population of cholinergic amacrine cells in the ferret's retina was identified as early as the day of birth, but their processes did not form discrete strata until the end of the first postnatal week. As development proceeded over the next five postnatal weeks, so the positioning of the cholinergic strata shifted within the IPL toward the outer border, indicative of the greater ingrowth and elaboration of processes within the innermost parts of the IPL. To examine whether these cholinergic strata play an instructive role upon the development of other stratifications which form within the IPL, one-week-old ferrets were treated with l-glutamate in an attempt to ablate the population of cholinergic amacrine cells. Such treatment was shown to be successful, eliminating all of the cholinergic amacrine cells as well as the alpha retinal ganglion cells in the central retina. The remaining ganglion cell classes as well as a few other retinal cell types were partially reduced, while other cell types were not affected, and neither retinal histology nor areal growth was compromised in these ferrets. Despite this early loss of the cholinergic amacrine cells, which are eliminated within 24 h, other stratifications within the IPL formed normally, as they do following early elimination of the entire ganglion cell population. While these cholinergic amacrine cells are present well before other cell types have differentiated, apparently neither they, nor the ganglion cells, play a role in determining the depth of stratification for other retinal cell types.


Development ◽  
1998 ◽  
Vol 125 (6) ◽  
pp. 1059-1066 ◽  
Author(s):  
D.K. Waid ◽  
S.C. McLoon

The different retinal cell types arise during vertebrate development from a common pool of progenitor cells. The mechanisms responsible for determining the fate of individual retinal cells are, as yet, poorly understood. Ganglion cells are one of the first cell types to be produced in the developing vertebrate retina and few ganglion cells are produced late in development. It is possible that, as the retina matures, the cellular environment changes such that it is not conducive to ganglion cell determination. The present study showed that older retinal cells secrete a factor that inhibits the production of ganglion cells. This was shown by culturing younger retinal cells, the test population, adjacent to various ages of older retinal cells. Increasingly older retinal cells, up to embryonic day 9, were more effective at inhibiting production of ganglion cells in the test cell population. Ganglion cell production was restored when ganglion cells were depleted from the older cell population. This suggests that ganglion cells secrete a factor that actively prevents cells from choosing the ganglion cell fate. This factor appeared to be active in medium conditioned by older retinal cells. Analysis of the conditioned medium established that the factor was heat stable and was present in the <3 kDa and >10 kDa fractions. Previous work showed that the neurogenic protein, Notch, might also be active in blocking production of ganglion cells. The present study showed that decreasing Notch expression with an antisense oligonucleotide increased the number of ganglion cells produced in a population of young retinal cells. Ganglion cell production, however, was still inhibited in cultures using antisense oligonucleotide to Notch in medium conditioned by older retinal cells. This suggests that the factor secreted by older retinal cells inhibits ganglion cell production through a different pathway than that mediated by Notch.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Guadalupe Álvarez-Hernán ◽  
Ruth Bejarano-Escobar ◽  
Ruth Morona ◽  
Agustín González ◽  
Gervasio Martín-Partido ◽  
...  

The LIM-homeodomain transcription factor Islet1 (Isl1) has been widely used as a marker of neuronal differentiation in the developing visual system of different classes of vertebrates, including mammals, birds, reptiles, and fish. In the present study, we analyzed the spatial and temporal distribution of Isl1-immunoreactive cells duringXenopus laevisretinal development and its relation to the formation of the retinal layers, and in combination with different markers of cell differentiation. The earliest Isl1 expression appeared at St29-30 in the cell nuclei of sparse differentiating neuroblasts located in the vitreal surface of the undifferentiated retina. At St35-36, abundant Isl1-positive cells accumulated at the vitreal surface of the neuroepithelium. As development proceeded and through the postmetamorphic juveniles, Isl1 expression was identified in subpopulations of ganglion cells and in subsets of amacrine, bipolar, and horizontal cells. These data together suggest a possible role for Isl1 in the early differentiation and maintenance of different retinal cell types, and Isl1 can serve as a specific molecular marker for the study of retinal cell specification inX. laevis.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Michelle E. McClements ◽  
Federica Staurenghi ◽  
Meike Visel ◽  
John G. Flannery ◽  
Robert E. MacLaren ◽  
...  

Vision loss caused by inherited retinal degeneration affects millions of people worldwide, and clinical trials involving gene supplementation strategies are ongoing for select forms of the disease. When early therapeutic intervention is not possible and patients suffer complete loss of their photoreceptor cells, there is an opportunity for vision restoration techniques, including optogenetic therapy. This therapy provides expression of light-sensitive molecules to surviving cell types of the retina, enabling light perception through residual neuronal pathways. To this end, the bipolar cells make an obvious optogenetic target to enable upstream processing of visual signal in the retina. However, while AAV transduction of the bipolar cells has been described, the expression of human opsins in these cell types within a model of retinal degeneration (rd1) has been less successful. In this study, we have expanded the optogenetic toolkit and shown successful expression of human rhodopsin driven by an ON-bipolar cell promoter (Grm6) in the rd1 mouse model using modified AAV capsids (AAV2.4YF, AAV8.BP2, and AAV2.7m8) delivered via intraocular injection. We also show the first presentation of ectopic expression of human cone opsin in the bipolar cells of rd1 mice. These data provide evidence of an expansion of the optogenetic toolkit with the potential to restore useful visual function, setting the stage for future trials in human patients.


2019 ◽  
Author(s):  
Phuong T. Lam ◽  
Christian Gutierrez ◽  
Katia Del Rio-Tsonis ◽  
Michael L. Robinson

ABSTRACTEarly in mammalian eye development, VSX2, BRN3b, and RCVRN expression marks neural retina progenitors (NRPs), retinal ganglion cells (RGCs), and photoreceptors (PRs), respectively. The ability to create retinal organoids from human induced pluripotent stem cells (hiPSC) holds great potential for modeling both human retinal development and retinal disease. However, no methods allowing the simultaneous, real-time monitoring of multiple specific retinal cell types during development currently exist. Here, we describe a CRISPR/Cas9 gene editing strategy to generate a triple transgenic reporter hiPSC line (PGP1) that utilizes the endogenous VSX2, BRN3b, and RCVRN promoters to specifically express fluorescent proteins (Cerulean in NRPs, eGFP in RGCs and mCherry in PRs) without disrupting the function of the endogenous alleles. Retinal organoid formation from the PGP1 line demonstrated the ability of the edited cells to undergo normal retina development while exhibiting appropriate fluorescent protein expression consistent with the onset of NRPs, RGCs, and PRs. Organoids produced from the PGP1 line expressed transcripts consistent with the development of all major retinal cell types. The PGP1 line offers a powerful new tool to study retinal development, retinal reprogramming, and therapeutic drug screening.


1994 ◽  
Vol 5 (1) ◽  
pp. 17-29 ◽  
Author(s):  
Charles L. Zucker ◽  
Berndt Ehinger ◽  
Magdalene Seiler ◽  
Robert B. Aramant ◽  
Alan R. Adolph

The development of five transplants of fetal retinal tissue to adult rat eyes was examined with the electron microscope. The transplants were of 9 to 10 weeks total age after conception in four cases and 20 weeks in one case. They were at stage E15 when transplanted. Transplants developed in both the epiretinal and subretinal spaces.The transplants were heterogeneously developed with some parts showing almost normal differentiation and others little. Subretinal transplants examined in this study were more developed than epiretinal grafts. Photoreceptor cells developed both inner and outer segments. Their synaptic terminals possessed output ribbon synapses with postsynaptic processes similar to those seen in normal retinas. In regions corresponding to the inner plexiform layer, the adult complement of synapses was seen, including advanced features such as serial synapses as well as reciprocal synapses at bipolar cell dyads. Incompletely differentiated synapses of both the amacrine and bipolar cell types were often observed, especially in the rat epiretinal transplants. Ganglion cell processes could not be identified with certainty.Although transplant cells were adjacent to host photoreceptor cells and pigment epithelium, obvious specializations or interactions were not observed. The experiments suggest that embryonic rat retinal cell transplants develop most or perhaps all of the structural components and neuronal circuitry necessary to transduce light and process some visual information.


2010 ◽  
Vol 104 (5) ◽  
pp. 2778-2791 ◽  
Author(s):  
Daniel K. Freeman ◽  
Donald K. Eddington ◽  
Joseph F. Rizzo ◽  
Shelley I. Fried

Electric stimulation of the CNS is being evaluated as a treatment modality for a variety of neurological, psychiatric, and sensory disorders. Despite considerable success in some applications, existing stimulation techniques offer little control over which cell types or neuronal substructures are activated by stimulation. The ability to more precisely control neuronal activation would likely improve the clinical outcomes associated with these applications. Here, we show that specific frequencies of sinusoidal stimulation can be used to preferentially activate certain retinal cell types: photoreceptors are activated at 5 Hz, bipolar cells at 25 Hz, and ganglion cells at 100 Hz. In addition, low-frequency stimulation (≤25 Hz) did not activate passing axons but still elicited robust synaptically mediated responses in ganglion cells; therefore, elicited neural activity is confined to within a focal region around the stimulating electrode. Our results suggest that sinusoidal stimulation provides significantly improved control over elicited neural activity relative to conventional pulsatile stimulation.


2016 ◽  
Vol 44 (5) ◽  
pp. 1245-1251 ◽  
Author(s):  
David A. Parfitt ◽  
Amelia Lane ◽  
Conor Ramsden ◽  
Katarina Jovanovic ◽  
Peter J. Coffey ◽  
...  

The photoreceptor cells in the retina have a highly specialised sensory cilium, the outer segment (OS), which is important for detecting light. Mutations in cilia-related genes often result in retinal degeneration. The ability to reprogramme human cells into induced pluripotent stem cells and then differentiate them into a wide range of different cell types has revolutionised our ability to study human disease. To date, however, the challenge of producing fully differentiated photoreceptors in vitro has limited the application of this technology in studying retinal degeneration. In this review, we will discuss recent advances in stem cell technology and photoreceptor differentiation. In particular, the development of photoreceptors with rudimentary OS that can be used to understand disease mechanisms and as an important model to test potential new therapies for inherited retinal ciliopathies.


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